A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing
Two-photon lithography (TPL) is a laser-based additive manufacturing technique that enables the printing of arbitrarily complex cm-scale polymeric 3D structures with sub-micron features. Although various approaches have been investigated to enable the printing of fine features in TPL, it is still ch...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-01-01
|
| Series: | Micromachines |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-666X/15/1/158 |
| _version_ | 1827371454552866816 |
|---|---|
| author | Rushil Pingali Harnjoo Kim Sourabh K. Saha |
| author_facet | Rushil Pingali Harnjoo Kim Sourabh K. Saha |
| author_sort | Rushil Pingali |
| collection | DOAJ |
| description | Two-photon lithography (TPL) is a laser-based additive manufacturing technique that enables the printing of arbitrarily complex cm-scale polymeric 3D structures with sub-micron features. Although various approaches have been investigated to enable the printing of fine features in TPL, it is still challenging to achieve rapid sub-100 nm 3D printing. A key limitation is that the physical phenomena that govern the theoretical and practical limits of the minimum feature size are not well known. Here, we investigate these limits in the projection TPL (P-PTL) process, which is a high-throughput variant of TPL, wherein entire 2D layers are printed at once. We quantify the effects of the projected feature size, optical power, exposure time, and photoinitiator concentration on the printed feature size through finite element modeling of photopolymerization. Simulations are performed rapidly over a vast parameter set exceeding 10,000 combinations through a dynamic programming scheme, which is implemented on high-performance computing resources. We demonstrate that there is no physics-based limit to the minimum feature sizes achievable with a precise and well-calibrated P-TPL system, despite the discrete nature of illumination. However, the practically achievable minimum feature size is limited by the increased sensitivity of the degree of polymer conversion to the processing parameters in the sub-100 nm regime. The insights generated here can serve as a roadmap towards fast, precise, and predictable sub-100 nm 3D printing. |
| first_indexed | 2024-03-08T10:40:39Z |
| format | Article |
| id | doaj.art-aa46046e5c4d4fcd957ee318363cfa39 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-08T10:40:39Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-aa46046e5c4d4fcd957ee318363cfa392024-01-26T17:45:34ZengMDPI AGMicromachines2072-666X2024-01-0115115810.3390/mi15010158A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive ManufacturingRushil Pingali0Harnjoo Kim1Sourabh K. Saha2G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USAG.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USAG.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USATwo-photon lithography (TPL) is a laser-based additive manufacturing technique that enables the printing of arbitrarily complex cm-scale polymeric 3D structures with sub-micron features. Although various approaches have been investigated to enable the printing of fine features in TPL, it is still challenging to achieve rapid sub-100 nm 3D printing. A key limitation is that the physical phenomena that govern the theoretical and practical limits of the minimum feature size are not well known. Here, we investigate these limits in the projection TPL (P-PTL) process, which is a high-throughput variant of TPL, wherein entire 2D layers are printed at once. We quantify the effects of the projected feature size, optical power, exposure time, and photoinitiator concentration on the printed feature size through finite element modeling of photopolymerization. Simulations are performed rapidly over a vast parameter set exceeding 10,000 combinations through a dynamic programming scheme, which is implemented on high-performance computing resources. We demonstrate that there is no physics-based limit to the minimum feature sizes achievable with a precise and well-calibrated P-TPL system, despite the discrete nature of illumination. However, the practically achievable minimum feature size is limited by the increased sensitivity of the degree of polymer conversion to the processing parameters in the sub-100 nm regime. The insights generated here can serve as a roadmap towards fast, precise, and predictable sub-100 nm 3D printing.https://www.mdpi.com/2072-666X/15/1/1583D printingmulti-photon polymerizationfemtosecond laser processingphotopolymerizationfinite element modelingdynamic programming |
| spellingShingle | Rushil Pingali Harnjoo Kim Sourabh K. Saha A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing Micromachines 3D printing multi-photon polymerization femtosecond laser processing photopolymerization finite element modeling dynamic programming |
| title | A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing |
| title_full | A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing |
| title_fullStr | A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing |
| title_full_unstemmed | A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing |
| title_short | A Computational Evaluation of Minimum Feature Size in Projection Two-Photon Lithography for Rapid Sub-100 nm Additive Manufacturing |
| title_sort | computational evaluation of minimum feature size in projection two photon lithography for rapid sub 100 nm additive manufacturing |
| topic | 3D printing multi-photon polymerization femtosecond laser processing photopolymerization finite element modeling dynamic programming |
| url | https://www.mdpi.com/2072-666X/15/1/158 |
| work_keys_str_mv | AT rushilpingali acomputationalevaluationofminimumfeaturesizeinprojectiontwophotonlithographyforrapidsub100nmadditivemanufacturing AT harnjookim acomputationalevaluationofminimumfeaturesizeinprojectiontwophotonlithographyforrapidsub100nmadditivemanufacturing AT sourabhksaha acomputationalevaluationofminimumfeaturesizeinprojectiontwophotonlithographyforrapidsub100nmadditivemanufacturing AT rushilpingali computationalevaluationofminimumfeaturesizeinprojectiontwophotonlithographyforrapidsub100nmadditivemanufacturing AT harnjookim computationalevaluationofminimumfeaturesizeinprojectiontwophotonlithographyforrapidsub100nmadditivemanufacturing AT sourabhksaha computationalevaluationofminimumfeaturesizeinprojectiontwophotonlithographyforrapidsub100nmadditivemanufacturing |